Stable sulphurized oils and the method of preparing same



Patented Jan. 15, 1946 STABLE SULPHURIZED onis AND THE arnon or PREPARING SAME I Joseph S. Wallace, Hammond, Ind., and Thomas E. Sharp, Chicago, 111., assignors to Standard 011 Company, Chicago, 111., a corporation of Indiana No Drawing. Application September 30, 1943, Serial No. 504,448

14 Claims.

The present invention relates to improvements in sulphurized oils and the method of preparing the same, and more particularly relates to improved sulphurized petroleum oils and the method of preparing the same.

It is well known in the art to employ as cutting oils sulphurized animal and/or mineral oil products. Usually these sulphurized oils are prepared by mixing elemental sulphur with the animal and/or mineral oil and heating the mixture at an elevated temperature above about 300F. for aperiod of time sufficient to obtain a product having the desired sulphur content. Such sulphurized oils are objectionable in that they are unstable and are susceptible to sedimentation, frequently amounting to 1% to 4%. This is an undesirable quality in sulphurized cutting oils, since they are often used in large plants where circulating systems and'tanks are employed in their distribution and the formation of sediment in such unstable oils often blocks the circulating lines and in other ways interferes with normal performance. Although substantially all of the initial sediment may be removed by mechanical means, such as by filtration, additional sediment forms upon aging of the sulphurized oil.

It is an object of the present invention to provide a stable non-emulsifiable sulphurized oil which is resistant tothe formation of sediment. Another object of the invention is to provide a sulphurized mineral oil which is substantially free of sediment. Another object of the invention is to provide an improved method of preparing stable sulphurized oils. Another object of the invention is to provide a method of inhibiting the formation of sediment in sulphurized oils.

We have discovered that the foregoing objects can be attained by our improved method of preparing sulphurized oils. In accordance with the present invention, the oil to be sulphurized, for example, a mineral oil of the desired viscosity, is mixed with about 2% to about 8%, and preferably with about 4% to about 6% of pulverized elemental sulphur, and the mixture heated at a temperature within the range of about 300 F. to about 360 F., and preferably within the range of about 335 F. to about 345 F. for a period of time sufficient to obtain a sulphurized oil having the desired sulphur content, usually from about 10 hours to about hours, preferably from about 12 hours to about 13 hours. At the end of the heating period the sulphurized oil is preferably cooled to a temperature of from about 175 F. to about 225 F., and preferably to a temperature within-the range of about 190 F. to about 210 F.,

and a small amount of a preferentially oil-soluble alkali metal sulphonate or an alkaline earth sulphonate such as a sodium sulphonate, potassium sulphonate, calcium sulphonate, etc., or an amine sulphonate, preferably an alkylolamine sulphonate such as triethanolamine sulphonate, is added to the sulphurized oil. Suitable sulphonates are the preferentially oil-soluble sulphonates, well known in the art as mahogany soaps obtained by the treatment of mineral oils with concentrated sulphuric acid, such as fuming sulphuric acid. The amount of preferentially oil-soluble sulphonate employed is within the range of about .001% to about 2%, and preferably within the range of about .005% to about 1%. While we prefer to add the mahogany soap to the sulphurized oil after it has been cooled, as above indicated, we can add the mahogany soap to the sulphurized oil before any substantial cooling.

If desired, the ,odor of the sulphurized oil may be improved by blowing the sulphurized oil after it has been cooled to about 200 F. with an oxygencontaining gas, such as air, for a period of about 30 minutes to about 90 minutes, and preferably for a period of about 45 to minutes. In case the sulphurized oil is air-blown, the oil-soluble sulphonate is suitably added during the blowing period. Still further odor' improvement may be obtained by adding a small amount, namely, about 0.1% of triethanolamine to the sulphurized oil when the temperature has dropped below about 150 F.

The amount of sediment which is present and which may possibly form on aging is reduced by at least 50% and in most cases by at least about whenthe sulphurized oils are prepared in the manner described. Inpractically all cases the total sediment amounts to less than 1%.

The following example is purely illustrative of the present invention and is not intended to be limitative thereof.

To gallons of a mineral oil having a Saybolt Universal viscosity at 100 F. of about 100 seconds were added 32 pounds of flowers of sulphur and the mixture heated in a still at a temperature of 340-350 F. for 12 hours. At the end of the sulphurization period the contents of the still were cooled to about 200 F. and blown with air for about 45 minutes, during which time about 2 pounds of sodium mahogany soap were added to the sulphurized oil. At the end of the blowing period after the temperature dropped to about F., about 0.1% triethanolamine was added to inhibit odor development.

The effectiveness of the herein described method of preparing stabilized sulphurized oils is demon-- strated by the data in the following table. The data show the amount of sediment found insulphurized oil prepared 'by the conventional methods and in accordance with the present invention with 2.0% sodium mahogany soap and with 0.25% sodium mahogany soap, immediately after sulphurization and after 30 to 35 days storage. Oil A was a 110 second viscosity (S. U. at 100 F.) oil, oil B was a 150 second viscosity (S. U. at 100 F.) 011, and oil C was a. 200 second viscosity (S. at 100 F.) oil.

Oil A, sedimentation 1 Oil B, sedi- Oil 0, sedimentation 1 mentation Method of sulphurization 34 so 35 Fresh days Fresh days Fresh days Conventional With 2% soda mahogany soap With 0.25% soda mahogany soap 1 Volume per cent.

ent invention is inadequate to form a stable permanent emulsion. The term non-emulsifiable sulphurized oil as used herein and in the appended claims means a sulphurized oil which is not readily or permanently emulsified with water.

' While specific ranges and proper have been given for the purpose of illustratiqn the'invention is not limited thereto, but is emanate of the following claims.

We claim: 5

1. The method of preparing a stable nonemulsifiable sulphurized mineral oil comprising sulphurizing the oil with elemental sulphur at a temperature from about 300 F. to about 360 F. and adding to the sulphurized oil an oil-soluble sulphonate selected from the class, consisting of alkali metal sulphonates, alkaline earth sulphonates and amine sulphonates in a small but suificient amount to inhibit the formation of sediment in the sulphurized oil.

2. The method of preparing a stable nonemulsifiable sulphurized mineral oil comprising sulphurizing the oil with elemental sulphur at a 5. The method described in claim 2 in which the oil-soluble sulphonate is an oil-soluble calcium sulphonate.

6. The method of preparing a stable nonemulsifiable sulphurized mineral oil comprising sulphurizing the oil with elemental sulphur at a temperature from about 300 F. to about 360 F., blowing the sulphurized oil with an oxygen containing gas and adding a small amount of an oil-soluble alkali metal sulphonate to the sulphurized oil.

7. The method of preparing a stable nonemulsiflable sulphurized mineral oil comprising sulphurizing the mineral oil with elemental sulphur at a temperature above about 300 F., blowing the sulphurized oil with an oxygen containing gas and adding-a small amount oi an oilsoluble sodium sulphonate to the sulphurized oil during the gas blowing period.

8. The method of preparing a stable non= emulsifiable sulphurized mineral oil comprising sulphurizing a mineral oil with elemental sulphur at a temperature within the range of about 330 F. to about 360 F. with elemental sulphur, cooling the sulphurized mineral oil to a temperature of from about 175 F. to about 225 F. and adding from about 0.001% to 2% of an oil-soluble'alkali metal sulphonate.

9. The method oi preparing a stable non-emulsifiable sulphurized mineral oil inhibited against sedimentation comprising sulphurizing a mineral oil with elemental sulphur at a temperature within the range of from about 300 F. to about 360 F. with sulphur, cooling the sulphurised oil tea-temperature of from about 175 F. to about 225 F., blowing the cooled sulphurized oil with an oxygen containing gas, and adding from about 0.001% to about 2% of preferentially oil-soluble alkali metal mahogany snap to the sulphurized oil during the gas blowing period.

10. A stable, non-emulsiflable sulphurized mineral oil comprising a sulphurized mineral oil prepared by reacting an oil with elemental sulphur at a temperature from about 300 F. to about-360 F., and an oil soluble sulphonate selected from the class consisting of alkali metal sulphonates, alkaline earth sulphonates and amine sulphonates, said sulphonate being employed in a small but suflicient amount to inhibit the formation of sediment in said sulphurized oil.

11. A stable, non-emulsifiable sulphurized mineral oil composition comprising a sulphurized mineral oil obtained by reacting a mineral oil with elemental sulphur at a temperature within the range of from about 330 F. to about 360 F. and from about 0.001% to about 2% of an oil soluble sulphonate selected from the class consisting of alkali metal suiphonates, alkaline earth sulphonates and amine sulphonates.

12. A stable, non-emulsifiable sulphurized mineral oil composition as described in claim 11 in which the oil soluble sulphonate is an oil soluble sodium sulphonate.

13. A stable, non-emulsifiable sulphurized mineral oil composition as described in claim 11 in which the oilsoluble sulphonate is an oil soluble potassium sulphonate,

14. A stable, non-emulsiiiable sulphurized mineral oil composition as described in claim 11 in 

